1. School of Materials Science and Engineering,Henan Polytechnic University,Jiaozuo　 454003,China; 2. Henan Key Laboratory of Materials on Deep-Earth Engineering,Jiaozuo　 454003,China; 3. Xinji Energy Co. ,Ltd. ,China National Coal Group Corp. ,Huainan　 232170,China

To address the issue of controlling the large deformation of surrounding rock in the roadway with more than 1 000 m depth,the project “strata control and intelligent mining technology in coal mines at 1 000 m depth” sponsored by National Key Research and Invention Program,proposes the “three-in-one” cooperative control technology,which is for bolting-grouting-destressing of coal mine roadways. The properties of “ high permeability,high strength and high bonding” are required for grouting materials. “ High permeability” can be achieved by reducing particle size and in- creasing interface wettability,“High strength” can be achieved by selecting minerals which hydrate rapidly and “High bonding” can be achieved by adding organic modifier which can improve wettability and bonding strength by mechani- cal bonding. In this study,the superfine sulphoaluminate cement clinker,anhydrite and lime were selected to make in- organic grouting material by optimizing their ratio. The particle size D95 of the materials was less than 7. 0 μm,the op- tional ratio of sulphoaluminate cement clinker,anhydrite and lime was 5 ∶ 4 ∶ 1. Nano lithium aluminum hydrotalcite (LiAl-LDH),which had the synergistic effect of lithium ion enhancement and nano-crystalline inducing crystalliza- tion,was synthesized to accelerate the hydration of inorganic grouting material. When the content of LiAl-LDH was 2%of inorganic grouting material,the compressive strength was increased by 145% and reached 12. 3 MPa. The am- phiphilic organic modifier was synthesized by “one-pot method”,when its content was 3% of inorganic grouting mate- rial,the contact angle between water and coal surface could be reduced from 72. 80° to 19. 23°. Hydrogen bonding was formed between the grouting material and the crevice surface,significantly improving the wettability of the interface and increasing the bonding strength of the interface. The micro-nano grouting materials were prepared by mixing inor- ganic grouting materials,nano-LiAl-LDH and organic modifier with 95% ,2% and 3% mass percentages,respectively. The initial and final setting time of the material was 8. 0 and 13. 0 min,respectively,and the compressive strength was 10. 2 MPa in 2 h. The bonding strength towards coal was greater than the tensile fracture strength of coal itself. The mi- cro-nano grouting material was applied to advanced grouting at Kouzidong mine. SEM observation showed that the slur- ry could pass through the 10 μm crevices and the cement stone had good bonding with crevice surface. After grouting, the pull-out force of anchor bolts was increased from 37 to 145 kN.

国家重点研发计划资助项目(2017YFC0603004);河南省自然科学基金资助项目(182300410207)

GUAN Xuemao,ZHANG Haibo,YANG Zhengpeng,et al. Research of high performance inorganic-organic composite grouting materials[J]. Journal of China Coal Society,2020,45(3):902-910.